Search results for "Retinal Vessel"
showing 10 items of 46 documents
Divergent Distribution in Vascular and Avascular Mammalian Retinae Links Neuroglobin to Cellular Respiration
2005
The visual function of the vertebrate retina relies on sufficient supply with oxygen. Neuroglobin is a respiratory protein thought to play an essential role in oxygen homeostasis of neuronal cells. For further understanding of its function, we compared the distribution of neuroglobin and mitochondria in both vascular and avascular mammalian retinae. In the vascular retinae of mouse and rat, oxygen is supplied by the outer choroidal, deep retinal, and inner capillaries. We show that in this type of retina, mitochondria are concentrated in the inner segments of photoreceptor cells, the outer and the inner plexiform layers, and the ganglion cell layer. These are the same regions in which oxyge…
FABC: Retinal Vessel Segmentation Using AdaBoost
2010
This paper presents a method for automated vessel segmentation in retinal images. For each pixel in the field of view of the image, a 41-D feature vector is constructed, encoding information on the local intensity structure, spatial properties, and geometry at multiple scales. An AdaBoost classifier is trained on 789 914 gold standard examples of vessel and nonvessel pixels, then used for classifying previously unseen images. The algorithm was tested on the public digital retinal images for vessel extraction (DRIVE) set, frequently used in the literature and consisting of 40 manually labeled images with gold standard. Results were compared experimentally with those of eight algorithms as we…
Retinal and choroidal vasculature changes associated with chronic kidney disease
2018
Retinal and choroidal microvascular changes can be related to renal impairment in hypertension and chronic kidney disease (CKD). The study examines the association between retinochoroidal parameters and renal impairment in hypertensive, non-diabetic patients. This is a cross-sectional study on Caucasian patients with systemic arterial hypertension with different levels of renal function. All subjects were studied by blood chemistry, urine examination, microalbuminuria and blood pressure. Complete eye examination was completed with swept source optical coherence tomography (SS-OCT) and optical coherence tomography angiography (OCTA) scans of macular region. Patients were divided in groups: L…
Contribution of nitric oxide synthase isoforms to cholinergic vasodilation in murine retinal arterioles.
2013
Abstract Nitric oxide synthases (NOSs) are critically involved in regulation of ocular perfusion. However, the contribution of the individual NOS isoforms to vascular responses is unknown in the retina. Because some previous findings suggested an involvement of inducible nitric oxide synthase (iNOS) in the regulation of retinal vascular tone, a major goal of the present study was to examine the hypothesis that iNOS is involved in mediating cholinergic vasodilation responses of murine retinal arterioles. Another subject of this study was to test the contribution of the other two NOS isoforms, neuronal (nNOS) and endothelial NOS (eNOS), to cholinergic retinal arteriole responses. Expression o…
Upregulation of antibody response to heat shock proteins and tissue antigens in an ocular ischemia model.
2011
PURPOSE. The aim of this study was to characterize the serum antibody reactivities occurring after ocular ischemia reperfusion. The time course of serum antibody responses was examined. METHODS. Wistar rats were exposed to transient ocular ischemia by elevating intraocular pressure to 130 mm Hg for 60 minutes. Axonal damage was evaluated on optic-nerve sections 2 and 4 weeks later. Blood samples collected before and several times after ischemia were used for antibody detection via customized protein microarrays. Different tissue antigens, including heat shock proteins (HSPs) and crystallins, were selected based on previous identification of antibody reactivities in studies on ischemic event…
Vessel painting of the microcirculation using fluorescent lipophilic tracers
2005
Flexible approaches to defining microvessel morphometry are useful in the study of both acute and chronic structural changes of the microcirculation. In this report, we examined the utility of the intravascular infusion of lipophilic carbocyanine tracers in the structural assessment of the retina, skin, lung, and colon microcirculation. The microvessel labeling technique, here termed fluorescent vessel painting, involved the intravascular injection of sulfonated lipophilic carbocyanine tracers. The utility of vessel painting in morphometry was assessed using morphometric comparisons with corrosion casting and 2-dimensional and 3-dimensional scanning electron microscopy. The comparisons demo…
Kinetic and static perimetry after 16 years and additional OCT-A analysis in eyes with long-lasting optic disc drusen
2021
The aim of the study is to evaluate the progression of visual field (VF) defects over 16 years of observation and to assess abnormalities in vessels and retinal nerve fibre layer (RNFL) thickness in patients with optic disc drusen (ODD). Both static automated perimetry (SAP) and semi-automated kinetic perimetry (SKP) were performed in 16 eyes of 8 patients (mean age 54 years) with ODD among 26 eyes of 13 patients examined 16 years before. The area of I2e, I4e, III4e, and V4e isopters was measured in deg2. The MD and PSD parameters were estimated using SAP. Optical coherence tomography angiography (OCT-A) was additionally performed in 16 ODD eyes and 16 eyes of 8 healthy subjects to estimate…
Optical coherence tomography angiography evaluation of peripapillary microvascular changes after rhegmatogenous retinal detachment repair
2021
PURPOSE To evaluate the radial peripapillary capillary plexus (RPCP) vessel density (VD) and the retinal nerve fiber layer (RNFL) thickness in eyes successfully treated with pars plana vitrectomy for primary rhegmatogenous retinal detachment. METHODS In this cross-sectional multicenter clinical study, eyes with a minimum 12-month follow-up were reexamined. The RPCP VD and RNFL thickness in the rhegmatogenous retinal detachment subfields of the affected eye (study group) were compared with the corresponding areas of the healthy fellow eyes (control group). RESULTS Fifty-three eyes were included in the study. A significantly lower RPCP VD and RNFL thickness were observed in those subfields af…
Aplasia of the retinal vessels combined with optic nerve hypoplasia, neonatal epileptic seizures, and lactic acidosis due to mitochondrial complex I …
1992
A newborn male with mitochondrial complex I deficiency suffered from neonatal epileptic seizures, which later developed into infantile spasms. The infant was blind due to aplasia of the retinal vessels and hypoplasia of the optic nerve. There was congenital lactic acidosis, which persisted in later life. The boy was microcephalic and retarded. Muscular hypotonia later shifted to spasticity. Succinic acid was increased in urine. We assume that the aplasia of the retinal vessels is due to damage of the retinal ganglion cells caused by the mitochondrial disease in the first 3 to 4 months of pregnancy.
Microvascular effects of the inhibition of dipeptidylpeptidase IV by linagliptin in nondiabetic hypertensive patients
2015
Recent studies suggest vascular benefits of dipeptidylpeptidase IV (DPP-IV) inhibition in patients with diabetes mellitus. Only little is known about potential vascular effects of DPP-IV inhibitors in nondiabetic individuals. The aim of this study was to investigate the effect of DPP-IV inhibition in a nondiabetic hypertensive population.This was a double-blinded, randomized, placebo-controlled, mechanistic study, comparing microvascular effects of the DPP-IV inhibitor linagliptin with placebo in nondiabetic individuals with a history of arterial hypertension. Twenty-one patients received 5 mg linagliptin (5 women; age 67.6 ± 6.0 years; mean ± SD), whereas 22 patients were randomized to pla…